Process for the preparation of butenoyl 1,3-cyclohexadienes

ABSTRACT

Process for the preparation of oxygenated unsaturated cycloaliphatic compounds useful as perfuming and odour-modifying agents in the manufacture of perfumes and perfumed products, and as flavouring and taste-modifying agents in the aromatization of foodstuffs in general and imitation flavours for foodstuffs, beverages, animal feeds, pharmaceutical preparations and tobacco products. Composition of matter relating to some of said oxygenated unsaturated cycloaliphatic compounds which are new and perfumeand flavouring compositions containing same.

United States Patent Schulte-Elte July 1, 1975 [54] PROCESS FOR THE PREPARATION OF 3,400,158 9/1968 Roberts 260/587 BUTENOYL 1,3 CYCLOHEXADIENES 3,436,421 4/1969 Rowland 260/587 [75] Inventor: Karl-Heinrich Schulte-Elte, Onex,

Geneva, Switzerland Primary Examiner-Howard T. Mars Assistant Examiner-Norman Morgenstern Assignee? Firmenich S-A', Geneva, Attorney, Agent, or FirmPennie & Edmonds Switzerland [22] Filed: Sept. 11, 1972 [57] ABSTRACT [21] Appl 287647 Process for the preparation of oxygenated unsaturated cycloaliphatic compounds useful as perfuming and [30] Foreign Application Priority Data odour-modifying agents in the manufacture of pen Sept. 13, 1971 Switzerland 13397/71 fumes and perfumed products, and as flavouring and taste-modifying agents in the aromatization of food- [52] US. Cl 260/586 R; 204/158 R; 252/522; stuffs in general and imitation flavours for foodstuffs, 260/348 C; 260/348.5 L; 260/488 R; beverages, animal feeds, pharmaceutical preparations 260/617 R; 260/631 R; 426/175; 131/17 R and tobacco pr lnt- Composition of matter relating to some of said of Search R, oxygenated unsaturated cycloaliphatic ompounds which are new and perfumeand flavouring References cued compositions containing same.

UNITED STATES PATENTS 11/1967 Surmatis 260/586 R 2 Claims, No Drawings 2' 3' PROCESS FOR THE PREPARATION OF CO CH" :CH H

BUTENOYL 1,3-CYCLOHEXADIENES containing a double bond in one of the positions indi- SUMMARY OF THE INVENTION cated by the dotted lines and wherein n is l or 2, or for- The compounds to which the present invention re- 5 ul'tl lates have the partlal formula CO CH2 CH2 CH3,

which process comprises I. a. oxidizing an alcohol of formula possessing a saturated or mono-unsaturated side chain VII and wherein the dotted lines represent a double bond in said side chain and a double bond in the ring. For simplicity in referring to the various compounds of the invention, their derivatives or precursors, the following nomenclature is used throughout this specification to by means of singlet oxygen, and b. successively treating the thus obtained oxidation products with a reducing agent to yield a mixture containing the compounds of formula IV (a,b,c), V

define the nature of the side chain:

a: double bond in position 2' or and V] b: double bond in position 3' H Saturated Slde Cham epoxidizing a compound of formula VII (a,b,c) and The above system of nomenclature WIll be appended to successively treating the thus Obtained epoxide the numbers designating the various formulae given with a basic agent to yield a Compound of formula hereinafter, to show the position of the double bonds v (tubs). Where they may occupy more than one position The above mentioned compounds of formula IV The invention relates to a new process for the prepa- 3O (HJLC), VH1 bf) and v] (ab C) most ofwhich are new ration of oxygenated cycloaliphatic compounds having possess intefesting organoleptic properties and, more the formula over, may be used as intermediates for the preparation of other compounds having useful fragrant and flavouring properties. It is in fact a further object of the present invention Iv endocyclic to prepare unsaturated cycloaliphatic ketones of fordouble bond mum V (a,b,c) exocyclic 1 2 double bond CO--CI1=CHCH3 containing an exoor endocyclic double bond in one of the positions indicated by the dotted lines and wherein R1 and R2 are the Same or dlfferem and each repre' whose class includes a compound wherein each of the seilisahydrogen ("Mower alkylradicalcom' substituents R and R represents a methyl radical, pnsmg from one to Carbon atomswhich compound is better known by the name of X represents a univalen t radical of formula figd [Cf HEN Chim Acta, 53, 541 CHMl (1970)]. Said process comprises treating a ketoalcohol of formula comprising a double bond in one of the positions 1nd1- cated by the dotted lines and wherein n is l or 2, or formula co-cn=cnca -CH0H-CH CH -CH on Ila and/or formula 2 with an acidic agent. R A further object of the present invention is to provide Y a process for preparing keto-alcohols of formula VI (a,b,c)

II (a,b,c) {endocyclic double bond wherein the substituents R and R have the meaning indicated above, and the symbol Y represents a univalent radical of formula III (a,b,c) exocyclic double bond containing a double bond in one of the positions indicated by the dotted lines and wherein the symbol Y has the same meaning as that indicated for formula VI (a,b,c), which process comprises oxidizing a diol of formula IV (a,b,c) or V (a,b,c).

BACKGROUND OF THE INVENTION One of the main objects of the aromatization of foodstuffs for instance is to restore the original quality and nature of the flavour, aroma and taste of a given foodstuff material. Very often in fact the organoleptic properties of foodstuffs particularly diminish or are somehow modified in the course of the processes of freezing and storage, or during the modifications, such as cooking or baking, to which the foodstuffs are subjected in order to yield an edible material.

In the past the aromatization was mainly achieved by using materials of natural origin. Nowadays, however, synthetic chemical compounds are used at an ever increasing rate. Said compounds possess the advantage of being available very often in unlimited quantities and at prices lower than those of the natural materials. Moreover, due to the fact that the flavouring character of a natural material is the result of the overall effect determined by the combination and interaction of each of its constituents, the effects achieved by said natural material are very often not as well reproducible as those obtained by the use of the pure synthetic compounds.

In the field of perfumery the man in the art has to solve a similar problem in attempting to reconstitute the olfactive notes of certain natural essential oils or extracts. The perfumers creativity however is continually boosted by the finding of new synthetic compounds, the organoleptic properties of which will enable him to introduce unprecedented olfactive characters or nuances into new phantasy perfume compositions.

As a consequence, the problem that the chemical industry has to solve is to satisfy the increasing demand of organoleptically interesting chemicals in order to better suit the specific needs of flavourists and perfumers.

The process of the present invention provides a novel and technically original solution to the problem set by the synthesis of unsaturated cycloaliphatic ketones of formula These compounds have been prepared in the past by dehydrogenation ofa cyclohexenic ketone to afford the corresponding cyclohexadienic derivative [Swiss Pat. No. 505,773].

The above indicated method has the disadvantage of i. affording the desired compounds only in poor yield and ii. using non easily accessible starting materials.

The process of the present invention does not offer the said disadvantages and, as a consequence, it can be conveniently exploited by the chemical industry.

Furthermore, the present invention describes the preparation of a new class of cycloaliphatic derivatives, the specific organoleptic properties of which enable the man in the art to further enlarge the choice of products to his disposal.

PREFERRED EMBODIMENTS OF THE INVENTION As mentioned above, according to the invention the compounds of formula IV (a,b,c), V (a,b,c) and VI (a,b,c) are prepared by oxidizing by means of singlet oxygen an alcohol of formula VII (a,b,c) and successively treating the thus obtained oxidation products with a reducing agent.

Singlet oxygen may be obtained by several known methods [see for instance Accounts of Chem. Research l, 104 (1968)]. A preferred method comprises irradiating triplet oxygen, i.e., molecular oxygen, either pure or in admixture with an inert gas, by means of actinic radiations and in the presence of an energy transfer sensitiser. Inert gases such as for intance helium, argon or nitrogen can be used in the above process. Conventional mercury or sodium vapour arcs can be used as sources of actinic radiations for irradiation purposes. Mercury vapour arcs are preferred since, under the action of their radiations, the oxidation reaction proceeds more uniformly and, consequently, higher yields of the desired oxidation product can be obtained.

As energy-transfer sensitisers, most current sensitisers such as for instance porphyrines, methylene blue, eosine, chlorophyll, 3',4,5,6-tetrachloro-2,4,5,7-tetraiodofluorescein (the sodium salt of which is called Rose-Bengale), xanthene and dinaphtylenethiophene can be used. For economic reasons, Rose-Bengale is preferred.

The oxidation by means of singlet oxygen according to the process of the invention can take place in the presence of an organic solvent which is stable to actinic irradiation, for instance an aliphatic or cycloaliphatic hydrocarbon such as hexane, octane or cyclohexane, or an aromatic hydrocarbon such as benzene, toluene 0r xylene, or an alcohol such as methanol, ethanol, propanol, butanol, isopropanol, sec-butanol or tert-butanol, or an ester such as ethyl acetate, butyl acetate and amyl acetate. A mixture of at least two of the above solvents can also be used. For best results it is preferable that all reagents be easily soluble in the solvent medium used. Methanol, ethanol or mixtures of these alcohols with benzene, toluene or ethyl acetate are preferably used.

The temperature at which the oxidation can be carried out can vary between wide limits. For simplicity and economy it is convenient to operate the oxidation between approximately and +50 C. However, at the lower temperatures of this range the formation of the products is slower and at the higher temperatures undesirable side reactions may occur. Consequently, preferred reaction temperatures are comprises between about 0 and 20 C or between about 10 and 20 C.

An alkali metal sulfite, hydrogen sulfite, thiosulfate, dithionate or pyrosulfite in aqueous solution may be advantageously used as reducing agent. Sodium sulfite is however preferred.

In accordance with the hereinabove described process, there is obtained a mixture comprising the com- The epoxide intermediates include a new compound, namely 2,6,6-trimethyll l-hydroxy-butyl1- 1,2- epoxy-cyclohexane.

The compounds of formula VI (a,b,c) may equally be Pounds of formula IV (a,b,c'), V (61,191 and VI (41.1w) 5 prepared by direct epoxidation of the unsaturated cywhich Compounds y be separated by means of P cloaliphatic derivatives of formula parative vapour phase chromatography, or fractional distillation. In this latter case spinning band columns 1 2 may be conveniently used. Y

The alcohols of formula VII (a,b,c) used as starting 10 materials in the above process of the invention may be VIII prepared according to the procedure described in German Offenlegungsschrift No. 2,022,216. Alcohols VII ,b, i l d 2,6,6 i th 1-[1-h d b 1] in accordance with the process described in German cyclohex-l-ene which is a new compound. Offenleg g 2,022,216-

The compounds of formula IV (a,b,c), V (a,b,c) and The compounds of formula VIII (a,b,c) used as start- Vl (a,b,c) include the following new compounds: ing materials in the above described method may be cisand trans-2,6,6-trimethyl-l-hydroxy-l-l I obtained in accordance with the procedure described hydroxy-but-Z-enyl]-cyclohex-2-ene, in Swiss Pat. No. 498,795 and German Offenlegungss- 2,6,6-trimethyl-1-hydroxy-l[ l-hydroxy-but-3-enyl1- chrift No. 2,022,216. The compounds of formula VIII cyclohex-Z-ene, (a,b,c) include a new compound, namely 2,6,6- 2,6,6-trimethyl- 1 -hydroxyl l-hydroxy-butyl trimethyll -butyryl-cyclohexl -ene.

Y As mentioned above a further object of the present and y y Y Y- invention is to provide a process for the preparation of -l y yy ly unsaturated cycloaliphatic ketones of formula 2-methylene-6,6-dimethyl- 1 -hydroxyl l-hydroxybut-3-eny1]-cyclohexane, R R 2-methylene-6,6-dimethyl-l-hydroxy-1-[ l-hydroxy- 00-01-14: H-C

butyl]-cyclohexane, 2,6,6-trimethyl-l-butyryl-1,2-epoxy-cyclohexane. I Whenever the specific cisor trans-isomerism is specifled, it is deemed to refer to the isomerism of the olefinic double bond in position 2- of the side chain of the whch process treatmg a (em-alcohol of molecule. mula Ila with an acid c agent. I

According to the process of the present invention v A fmneral or e acld Such as hxdrochloflc compounds V (mbc) are also prepared by epoxidizing phuric, phosphor c, p-toluenesulphonic or trifluorothe compounds of formula VII (a,b,c) and successively acetlc or dlhtfnnaceous earths may be treating the thus obtained epoxide with a basic agent. vantageously used as acldlc f The epoxidation may be carried out by means of an or- The reachoh y he earned out m an Organic ganic peracid of the class generally used to this end 40 vent, preferably an mert one, such as benzene, dloxan, such as performic acid, peracetic acid, trifluoroacetic tetrahydroturan ethyl acetate, or a mlXtuFe of at acid, perbenzoic acid, monochloroperbenzoic acid, least two of the'sald Solvents, and Preferably at a hmonoperphthalic acid in an inert organic solvent such Perature eomprlsed between about C and the hellas e.g. chloroform, methylene chloride, trichloroethmg temperature of the h e Solventylene or benzene in a buffered medium. An alkali metal The emp t h g mdleated ahOVe y however acetate may be conveniently used as buffer salt. y W'thlh Wider hmlts and temperatures hlgher The next step f the reaction, L h treatment f lower than those indicated may be used. According to the obtained epoxidation products, formally consists in a Preferred embodiment of the Present P e of the the opening of the epoxide ring to afford compounds V invention, the reaction is carried out in a dioxan solu- (a,b,c). Said ring opening may be carried out by me tion and at a temperature comprised between about 90 of a basic agent in accordance with the procedure usuand about 100 C. The compounds of formula Ila, used ally employed to this end in organic chemistry [cf.; D. as starting materials for the above mentioned process, J. Cram and G. S. Hammond, Organic Chemistry, together with their analogues of formula II (b,c) and III McGraw Hill, Inc., New York 1959), pp. 204-5; H. O. (a,b,c) are prepared according to a process of the pres- House, Modern Synthetic Reactions. W. A. Benjamin, ent invention by oxidizing a diol of formula IV (a,b,c) Inc., New York (1965), pp. 1 12-3]. The lithium salt of or V (a,b,c), respectively. ethylenediamine is preferred. The said oxidation may be carried out by the action The following reaction scheme will illustrate the of silver carbonate in the presence of diatomaceous above described process: earth, or of an oxygen-containing derivative of a transi- R R R R epoxidation ring opening P l VII (a,b,c) V (a,b,c)

tion metal such as chromium, manganese or nickel. Preferred oxidation agents include manganese dioxide and chromium trioxide, this latter being preferably used in the presence of an organic base such as pyridine lcf. e.g.: J. Org. Chenr, 26, 4814 (1961)].

Said oxidation can be carried out in an inert organic solvent such as an aliphatic or cycloaliphatic hydrocarbon, e.g. pentane, hexane or cyclohexane.

According to a specific embodiment of the present process of the invention compounds Ila and llla can be obtained by oxidation by means of both manganese dioxide and chromium trioxide in pyridine, whereas compounds llb and lllb are preferably obtained by the action on diols lVb and Vb of chromium trioxide in pyri' dine.

The compounds of formula II (a,b,c) and Ill (a,b,c) include the following new compounds:

2,6,6-trimethyl-1-hydroxy-1-butyryl-cyc1ohex-2-ene,

cisand trans-2-methylene-6,6-dimethyl-l-hydroxy- 1-[but-Z-enoyll-cyclohexane,

2-methylene-6,6-dimethyl-1-hydroxy-l{but-3- enoyl]-cyclohexane and 2-methylene-6,6-dimethyl- 1 -hydroxyl -butyrylcyclohexane.

Compounds lIa can furthermore be obtained by isomerisation of the exocyclic double bond of compounds llla by means of an acidic or basic isomerising agent. Said isomerisation is advantageously promoted by a Lewis-type acid such as AlCl BF SnCl, or iodine. This latter is preferred. As basic isomerising agent lithium-ethylenediamine can be used instead.

Carbinols Vll (a,b,c) can further be converted into their corresponding esters, such as formates, acetates, propionates, butyrates e.g., in accordance with the usual techniques of esterification [cf. e.g.: L. F. Fieser and M. Fieser, Organic Chemistry, Reinhold Publ. Corp., New York (1956), p. 174]. Specifically, by treating carbinols Vll (a,b,c) with acetyl chloride in the presence of an organic base such as a tertiary amine, e.g. dimethylaniline, there are obtained with good yields the corresponding acetates of formula ococn R1 R2 I 3 CH-Z IX (a.,b,c)

wherein R and R have the same meaning as indicated above and the symbol Z represents a univalent hydrocarbon radical of formula containing a double bond in one of the positions indicated by the dotted lines and n is 1 or 2, or of formula The mentioned esters can be converted into their corresponding mono-epoxide derivatives according to the usual procedure of epoxidation [see eg the above described epoxidation of compounds Vll (a,b,c)]. Specifically, acetates IX (a,b,c) can be epoxidized to yield the compounds of formula X (a,b,c)

The compounds of the hereinabove given formulae lX (a,b,c) and X (a,b,c) include the following new compounds:

cisand trans-2,6,6-trimethy1-l-[ 1-acetoxy-but-3- enyl]-cyc1ohex1-ene, 2,6,6-trimethyl-l-[ 1 acetoxy-but-3-enyl]-cyclohexl-ene, 2,6,6-trimethyl'1-[1-acetoxy-butyl]- cyclohex-l-ene, cis and trans-2,6,6-trimethyl-ll-acetoxy-but-2-enyl]-1 ,2-epoxy-cyclohexane,

2,6,6-trimethyl-1-[ l-acetoxy-but-3-enyl1- 1 ,2-epoxycyclohexane and 2,6,6-trimethy1-1-[1-acetoxy-butyl1-1,2-epoxycyclohexane.

In terms of chemical structure, the new compounds of the invention are related to the known compounds disclosed in German Offenlegungsschrift No. 2,022,216 and Swiss Pat. No. 524,320, but their olfactive and flavouring characteristics differ significantly from those of said previously described compounds. This underlines the impossibility of predicting precise organoleptic characteristics from chemical structure. As is well known from other classes of compounds also, the position ofa double bond in the molecule, the steric configuration and the nature of the specific substitution, in a higher homologue e.g., can substantially modify the odour and/or flavour of a given substance.

Specifically the new compounds of the invention 3 have an odour reminiscent of certain plants of the family of papilionaceae, in particular of foenugreek. Typically, 2,6,6-trimethyl-l-hydroxy-l-butyryl-cyclohex- 2-ene and 2-methylene-6,6-dimethyl-l-hydroxy-l-[lbut-2-enoyl]-cyclohexane develop and enhance the said olfactive note. These two compounds may be used in particular as perfume modifying agents in fine perfumery, specifically for enhancing the natural effect of certain compositions of the flowery type such as jasmin or jasmin-like compositions.

The new compounds of the invention may equally develop various olfactive notes such as woody, amber-like or even, in some instances, fruity notes. Typically, 2- methylene-6,6-dimethyl-l-hydroxy-l-butyrylcyclohexane, 2,6,6-trimethyl- 1-1 1 -acetoxy-but-3- enyl]-1,2-epoxy-cyclohexane, 2,6,6-trimethyl-l lacetoxy-butyH-cyclohex-l-ene and 2,6,6-trimethyl-ll-hydroxy-butyl1-1,Z-epoxy-cyclohexane are reminiscent of patchouli or vetyver oil and can be used for modifying or enhancing the woody notes of certain perfume compositions. It has been observed that the character of 2,6,6-trimethyl-l-[ l-hydroxybutyl]-cyclohex- 2-ene, 2,6,6-trimethyl- 1 -hydroxyl -butyrylcyclohexane and 2,6,6-trimethyl-1-l1acetoxy-but-3- enyl]-cyclohex-1-ene is reminiscent of the scent of certain fruits, particularly of gooseberries. This specific effect is novel and original in the art of modern perfumery. The said compounds satisfy therefore a special need of the perfumers, who in recent years tried to develop new fragrances possessing fruity tones.

The proportions of the new compounds to be used in such compositions can vary within wide limits. For example, in the preparation of perfume compositions, interesting effects can be achieved when the compounds of the invention represent as little as 1% or as much as 5 or of the total composition; but, depending upon the effect desired. the proportion of the compounds of the invention may be increased to 20 by weight, or even more.

The new compounds of the invention possess also very interesting flavouring properties. In most instances, they impart to the products to which they are added a woody note. They can moreover develop various flavouring notes such as fruity, fatty or green notes. They find a particularly useful application in the aromatization of foodstuffs such as jam, marmelade, yoghourt, bakery or confectionery products and preserves. In some instances, they may enhance the citrusfruit characters of beverages such as those having a lemon or sweet-lime character.

The particular organoleptic properties of the new compounds of the invention enable their use for the aromatization of tobacco products, the woody and fruity notes being particularly appreciated by the smokers.

The proportions used for flavouring purposes can vary within a wide range. Typically, interesting flavouring effects can be achieved with amounts ranging from about 0.1 to 10 ppm, based on the weight of the product flavoured. However, in order to obtain special flavour results, this amount can be increased to about 100 When the compounds of the invention are used in flavouring compositions, in admixture with other flavouring agents and/or inert carriers or diluents, they may typically comprise from about 0.1 7c to about l5 of the total weight of the composition, and. in many cases, amounts from 1 to 10 by weight will give the best results.

In all cases, the ranges of proportions given above may be varied, in order to achieve specific organoleptic effects.

The term foodstuff. as used in the course of the present specification, is used broadly: it is deemed to designate materials such as coffee, tea and cocoa.

The invention is better illustrated by the following examples, wherein the temperatures are indicated in degrees Centigrade.

EXAMPLE] A base perfume composition of the Chypre type has been prepared by admixing the following ingredients (parts by weight):

a-Phcnylethylacetatc 3U Undeccnal 10% 100 a-Methyldecanal l "/1 Z0 Coumarin 60 Vanillin Musk ketone 55 Cyclopentadecanonc 107! 3O a-lsomethyliononc 60 Oak moss absolute 20 Lahdanum absolute l0 Synth. galhanum ll) Synth. castoreum 2() Methyl Z-pentyL3-oxo-cyclo pentyl acetate 50 Bcnzyl acetate 100 lndol l0 1 l0 Hcxylcinnamic aldehyde 50 Synth. rose 50 Patchouli 20 Synth. bergamot 200 Diethyl phthalatc 100 1000 in diethylphthalate When to 90 g of the above base composition there are added 10 g of a 10 70 solution of 2,6,6-trimethyl-lhydroxy-l-butyryl-cyclohex-2-ene in diethyl phthalate, there is obtained a perfume composition possessing a novel floral tone of a very natural richness.

Analogous results were obtained by adding to the base composition in the same proportions, cisor trans- 2-methylene-6,6-dimethyll-hydroxy-l -[but-2-enoyl]- cyclohexane.

EXAMPLEZ A base perfume composition of the after-shave lotion type has been prepared by admixing the following ingredients (parts by weight):

Menthol l0 Eugenol 50 Coumarin 2U Muscone 10 71 2O Phenylethyl alcohol 120 Lavender oil 2 l 0 Pimento oil 40 Cinnamon oil 5 Synth. bergamot 270 Cyclopentadecanone 10 30 Methyl 2 pentyl-3-oxo-cyclopentyl acetate Oak. moss absolute l5 Benzyl salicylate 2O lsobutyl salicylate Geranium Bourbon oil 70 Musk ketone 20 95 71 ethanol 50 in 95 '2' ethanol EXAMPLE3 A base perfume composition has been prepared by admixing the following ingredients (parts by weight):

Musk ketone 10 Dodecenal 10% 20 Undecenal 107: l0 Angelica roots 10 '7! 20 Methyl 2-pentyl-3-oxo-cyclopcntyl acetate 10 "/1 50 Ylang 30 Hydroxyeitronellal 20 Galbanum oil 10 Coriander oil 40 Cedar oil 70 Eugenol Amyl salicylate 4O Citroncllol 5U a-lsomcthylionone 50 C itral l0 Vcty eryl acetate 20 Lavender oil Geranium Bourbon Oak moss absolute 5O /r 20 Brazilian mint oil 20 Artificial bcrgamot I00 Artificial ncroli 9O Phenylethyl alcohol Diethylphthalatc 20 -Continued in diethylphthalatc When to 98 g of the above after-shave lotion type base composition there are added 2 g of Z-methylene- 6,6-dimethyl-l-hydroxy-l-butyryl-cyclohexane there is obtained a perfume composition possessing, by comparison with the base composition, a pleasant woody, green character.

Analogous results were obtained by adding to the given base composition in the same proportions, 2,6,6- trimethyl-l l-acetoxy-but-3-enyl1-l ,2-epoxycyclohexane, 2,6,6-trimethyl-l-[ l-acetoxy-butyl1- cyclohex-l-ene or 2,6,6-trimethyl-l-[ l-hydroxybutyll-l ,Z-epoxy-cyclohexane.

EXAMPLE4 A perfume base composition for lipsticks was prepared by admixing the following ingredients (parts by weight):

Artificial Jasmin 150 Phenylethyl alcohol 100 Artificial rose 150 Civetone 1O 71 Z p-Hydroxy-phenyl-butan-3-one l0 7: l0 Nerol 100 Heliotropine 50 Petitgrain bigarade 50 Mcthyl-hexylcarbinol 30 Citronellyl acetate 60 Ylang 50 Cyclopentadecanolide l0 /2 10 Brazilian mint oil 10 Cinnamon of Ceylon l0 7: l0 Geranium Bourbon 4O Linalol 60 a-lonone O Diethylphthalate 5t) in diethylphthalate By adding to 95 g of the hereinabove given base composition 5 g ofa l0 solution of 2,6,6-trimethyl-1-[ lacetoxy-but-3-enyll-cyclohex-l-ene in diethylphthalate there is obtained a new composition possessing by comparison with the base composition a well defined fruity and sweeter character.

Analogous results were obtained by replacing 2,6,6- trimethyll l-acetoxy-but-3-enyl]-cyclohex-l-ene by 2,6,6-trimethyl-l-[1-hydroxy-butyll-cyclohex-l-ene.

EXAMPLE 5 A base perfume composition for room-spray products was prepared by admixing the following ingredients (parts by weight):

Decanal l0 71 50 Noncnal l 71 20 4Mcthyl2-l 2-mcthyl-propen2-yl tetrahydropyran I0 71 l0 Geranyl acetate 30 Geranium Bourbon 20 Methyl 2-pentyl3-oxo-cyclopentyl acetate 50 Phenylethyl alcohol 100 Geranyl nitrile l() Geranyl acetone Linalol 4t) Benzyl acetate 60 Hexylcinnamic aldehyde 30 Petitgrain bigarade 5U Lavender oil 20 Artificial bergamot l0() Artificial rose 70 -Continued Amyl salicylate 20 a-lsomethyliononc 50 C yclopentadccanolide 10 3O Ylang 50 Myrcenyl acetate Diethylphthalate lOO i000 By adding to g of the above given base perfume composition l0 g of a 10 solution of 2,6,6-trimethyll-[ l-hydroxy-butyl]-cyclohexl -ene in diethylphthalate there is obtained a new composition possessing by comparison with the base composition, an improved natural and fresh fruity character.

EXAMPLE 6 A Tutti-Frutti flavouring composition was prepared by admixing the following ingredients (parts by weight):

Vanillin 20 Allyl caproate l0 Citral 20 Amyl butyrate 35 Orange oil 45 Ethyl butyrate 75 Ethyl acetate 185 Amy] acetate 185 Lemon oil 415 2,6,6-Trimethyl- 1 -hydroxyl -butyryl-cyclohex-2-ene (10 g) was added to 990 g of the above mixture which was then called test" composition. A control" composition was prepared by adding l0 g of additional lemon oil to 990 g of the above mixture.

The test and control" compositions were added to the food products described hereinafter in the proportions shown for kg of material to be flavoured.

Cake 20 g Pudding 5 10 g Hard Candies l5 20 g Hard Candies: 100 ml of sugar syrup (prepared by dissolving 1 kg of sucrose in 600 ml of water) and 20 g of glucose were mixed together and slowly heated to The flavour was added and the mass was allowed to cool and harden.

Pudding: to 500 ml of warmed milk were added with stirring a mixture of 60 g of sucrose and 3 g of pectin. The mixture was boiled for a few seconds and the flavour was added. The mixture was allowed to cool.

Cake: the following ingredients were mixed together:

100 g of vegetable margarine, l.5 g of sodium chloride, 100 g of sucrose, 2 eggs and 100 g of flour. The flavour was added and the mass was cooked for 40 minutes at The finished foodstuff samples were tested by a panel of trained persons who had to express their views about the flavour of the samples. All members of the panel declared that the test" samples had a more round taste than the control and at the same time a woody character. Moreover, the test samples presented a fruity note and conferred to the foodstuff materials a character of dried fruit.

When in the above example 2,6,6-trimethyl-l-hydroxy-l-butyryl-cyclohex-Z-ene was replaced by Z-methylene-6,6-dimethyl-l-hydrxyl-butyryl-cyclohexane. analogous results were observed.

EXAMPLE 7 7 g of a l solution of 2,6,6-trimethyl-l-[ lacetoxybut-B-enyl]-cyclohex-l-ene in 95 "/1 ethyl alcohol were sprayed on 100 g of a tobacco mixture of the american blend type. The tobacco thus flavoured was used to manufacture test" cigarettes. the smoke of which was then subjected to organoleptic evaluation by comparison with non-flavoured cigarettes (control"). The tobacco used to prepared the control" cigarettes was preliminarily treated with 95 70 ethyl alcohol. The panel of experts unanimously defined the taste of the test" cigarettes as being sweeter than that of the control" cigarettes; moreover, the smoke possessed a note with an improved woody and fruity character.

By following the same procedure as that given above, 2-methylene-6,6-dimethyll -hydroxyl -[but-2-enoyl]- cyclohexane and 2,6,6-trimethyl-l-hydroxy-l-butyrylcyclohex-2-ene where evaluated. The smoke of the cigarettes flavoured by these two compounds possessed a woody note of the cedar wood type and was reminiscent of certain woody characters of some oriental tobaccos.

EXAMPLE 8 The vehicle used for testing the flavour compounds was a 65 solution of cane sugar in tap water. The flavour compounds were incorporated in this sugar syrup in the form of l or 1 per 1,000 by weight solutions in 96 ethyl alcohol. The concentration of the flavour compounds in the sugar syrup varied between about 0.1 and 1.0 g for 100 liters of syrup according to the varying strength of flavour compounds. Samples of each flavoured sugar syrup were submitted to the members of the tasting panels. After tasting the samples each member had to give an evaluation of each flavour compound in terms of descriptive words. The observed organoleptic evaluations are indicated in the following table.

ing to French Pat. No. 1,591,031] (purity 92 0.2 g of Rose Bengale and l g of sodium acetate in 160 ml of anhydrous methanol, through which a stream ofpure oxygen is passed, is irradiated in a photochemical reaction vessel at a temperature of about 15 by means of a mercury vapour lamp (type Philips HPK 125 Watt). The absorption of gas at the beginning of the irradiation is 12 ml per minute. This absorption gradually decreases. Towards the end of the irradiation an additional 0.2 g of Rose Bengale is added. After 6 hours the mixture has absorbed 2,850 ml of 0 An analysis by means of vapour phase chromatography reveals that the starting product has practically disappeared.

b. Reduction of the oxidation mixture obtained according to (a) 95 ml of the cooled solution (05) obtained directly according to the method indicated in the above para graph a) are added to a mixture of 5 g of Na SO in 200 ml of water, while vigorously stirring. The whole is left at for 2 hours. The reaction mixture is then extracted several times with ether and the combined organic extracts are washed with water, neutralized with a 5 solution of NaHCO and dried over anhydrous MgSO The volatile portions are evaporated under reduced pressure, and the resulting residue is subjected to a distillation to give 9.5 g of an oily product which, on separation by means of preparative vapour phase chromatography, yields the following products: trans-2 ,6 ,6-Trimethyll -[but-2-enoyl]-1 ,2-

epoxycyclohexane: yield 48 b.p. 80/0.5 Torr; n,,

1R l700-l630 and 968 cm NMR: 1.0 and 1.06 (6H, 25); 1.08 (3H, s); 1.92 (3H,

d, .1 7 cps); 6.1-7.2 (2H, m) 5 ppm MS M 208 (0.1); m/e: 193 (0.1); 151 (5); 139 (12); 125 (14); 111 (64); 95 (5); 82 (12); 69 (100); 41 (62); 29 (8).

threo-2-Methylene-6,6-dimethyl- 1 -hydroxyl lhydroxy-but-2-enyl]-cyclohexane: yield 30 7c; oil; 11 1.4890; (1 0.9854

1R 3600, 970 and 890 cm" but-3-enoyl I-cyclohexl -enc 4. 2.6.6-Trimcthyl-l-[l-hydroxybutyl 1 .Z-epoxy-cyclohexanc 5. 2,6.6-Trimcthyl-l-ll-acctoxybutyl I-ey-clohcxl -ene 6. 2 Methylene-b.6-dimethyl-lhydroxyl -but \'ryl-cyclohexanc 7. 2,6.6-Trimethyl-l-hydroxy-l butyryI-cyclohex-lcne 8. Z-Mcthylene-6.6-dimcthyl-lhydroxyl hut-Z-cnoyl l'cyclohexanc slightly fruity 9. 2.6.6-Trimcthyl-l-butyryl-l.2-

epoxy-cyclohexanc woody. earthy woody, green. minty fatty. slightly woody woody. swecty. fruity woody. grccn, slightly fruity fruit dried fruit direction EXAMPLE 9 a. Oxidation of 2,6,6-trimethyl-l-[lhydroxy-but-2- 65 enyl]-cyclohex-l-ene A mixture of 20.5 g of 2.6,6-trimethyl-1-[lhydroxybut-Q-enyl]-cyc1ohex-l-ene [prepared accord- NMR 0.86 and 1.0 (6H, 2s); 1.69 (3H, d, J=5 cps);

4.23 (1H, m); 4.82 (2H. m); 5.5 (2H, m) 8 ppm MS1M 2lO(O.l);m/e: 192(1); 177(O.5); 139 (18); 125 (9); 99 (4); (30); 82 (10); 69 (ll); 55 (12); 43 (100); 27 (6).

2,6,6-Trimethyl1-hydroxy-1[l-hydroxy-but-Z-enyllcyclohex-Z-ene: yield 4 7r.

1R 3500, 3070, 1635, 850 cm MS: M 210().

By oxidation by means of M110 there is obtained a compound whose analytical data are identical with those of 2,6,6-trimethyl-l-hydroxy-l-[but-2-enoyl]- cyclohex-2-ene [see Ex. 14].

EXAMPLE a. Oxidation of 2,6,6-trimethy1-1-[ l-hydroxy-but-3- enyl]-cyc1ohex-1-ene A solution of 19.6 g of 2,6.6-trimethy1-1-[ 1-hydroxybut-3-enyl]-cyclohex-1-ene [prepared according to Helv. Chim. Acta, 53, 541 (1970)], 0.2 g of Rose Bengale and 0.5 g of sodium acetate in 150 ml of anhydrous methanol is subjected to 'an oxidation by the action of oxygen in the singlet state following the same process as that described in Example 9. After 7 hours the mixture has absorbed 2,5 80 ml of O: at a rate of absorption of 10 ml per minute at the beginning of the irradiation. b. The mixture obtained by the oxidation by means of oxygen in the singlet state according to the method described in Example 9, paragraph (b), is subjected to a reduction using 10 g of Na- SO in 100 m1 of water. After 3 hours at about 20, the reaction mixture is extracted with ether and the combined organic extracts are subjected to the usual treatments to yield aproduct of b.p. 40120/0.02 Torr, 17.6 g. On separation by means of preparative vapour phase chromatography the following products are obtained: 2,6,6-Trimethyl-1-[but-3-enoyl]-l ,2epoxycyclohexane: yield 42 7c; n 1.4721; c1 =0.9781 1R 3080, 1700, 1640, 990 and 915 cm NMR: 1.02 and 1.05 (6H, 2s); 1.1 (3H, s); 3.2 (2H,

m); 4.8 and 6.2 (3H) 8 ppm MS:M =200(0.1);m/e: 193(1); 177(1); 151 135 (2); 123 (8); 111 (4); 95 (3); 81 (2); 69 (100); 55 (18); 41 (29).

threo-2-Methylene-6,6-dimethyl-l-hydroxy-1-[1- hydroxy-but-2-enyl]-cyclohexane: yield 25 "/c; 1.5049; (1 1.007

1R 3623, 3572, 3085, 1645, 1640 and 890 cm NMR 0.86 and 1.08 (6H, 3.7 (1H, m); 4.7-6.1

(3H); 4.82 and 5.0 (2H, 2m) 6 ppm MS M 210(0.1);m/e: 192(1); 169(3); 151 (2); 140 (25); 125 (27); 107 (5); 95 (38); 81 (10); 69 (15); 55 (12); 43 (100); 27 (8).

erythro-2-Methylene-6,6-dimethyl-1-hydroxy-l-[ lhydroxy-but-Z-enyl]-cyclohexane: yield 8 7r; 11 1.5029; 11, 0.9954

IR 3620, 3565, 3080, 1645, 1640, 990, 910 cm NMR 0.88 and 1.05 (6H, 2s); 4.02 (1H, m); 4.8-6.2

(3H); 4.86 and 5.02 (2H, 2m) 8 ppm 16 MS:M+=210(0.1);m/e: 192(1); 169(12);151 (3); 140 (15); 133 (15); 125 (18); 109 (8); (40); 81 (15); 69 (33); 5.5 (20); 43 27 (8).

2,6,6-Trimethyl- 1 -hydroxy- 1 l-hydroxy-but-3-enyl]- cyclohex-Z-ene: yield 3 70. By oxidation of this compound with CrO /pyridine there is obtained 2,6,6- trimethyl-l-hydroxy-1-[but-3-enoyl]-cyclohex-2-ene [see Ex. 14].

EXAMPLE 1 1 a. Oxidation of 2,6,6-trimethyl-l-[ 1-hydroxy-butyl]- cyclohex-l'ene A solution of 19.8 g of 2,6,6-trimethyl-1-[ l-hydroxybutyl]-cyclohex-1-ene (prepared by partial hydrogena tion of 2,6,6-trimethyl-1-[1-hydroxy-but-3-enyl]- cyclohex-l-ene in the presence of Raney nickel; 1.4891; (1 0.9285), 0.2 g of Rose Bengale and 0.5 g of anhydrous sodium acetate in 160 m1 of anhydrous methanol is subjected to an oxidation by the action of oxygen in the'singlet state (sensitized photooxygenation) according to the process described in Example 9.

The rate of absorption is 9 ml of O per minute.

b. The mixture obtained by the oxidation by means of oxygen in the singlet state following the method described in Example 9, paragraph (b), is subjected to a reduction using 10 g of Na SO in 200 ml of water. After 3 hours at about 20 the reaction mixture is extracted with ether and the combined organic extracts are subjected to the usual treatments to yield a product of b.p. 40-120/0.01 Torr; 18 g. On separation by means of vapour phase chromatography there are obtained: 2,6,6-Trimethyl-1-butyryl-1,2-epoxy-cyclohexane:

yield 50 m} 1.4619; a 0.9618 IR 1710 cm NMR: 1.02 and 1.04 (6H, 25); 1.08 (3H, s) 8 ppm MS:M =210(0.1);m/e:203(0.5); 167(3); 153(3); 140(3); (46); 111 (22); 95 (7); 84 (13); 69 (44); 55 (43); 43 (100 27 (10).

threo-2-Methylene-6,6-dimethyl-1-hydroxy-1-[1- hydroxy-butyl]-cyclohexane:yield 27 m.p. 64

1R 3623, 3565, 3080, 1640 and 895 cm NMR 0.87 and 1.08 (6H, 2s); 3.87 (1H, m); 4.75 (2H,

m) 8 ppm MS:M =212(1);m/e: 194(1); 179(1); 151 (3); (33); 125 (50); 109 (7); 95 (35); 84 (12); 69 (18); 55 (25 43 (100); 29 (10).

erythro-2-Methy1ene-6,6-dimethyl-1-hydroxy-1-[1- hydroxy-butyl]-cyclohexane: yield 4 7c; m.p. 56

1R 3629, 3558, 3085, 1645 and 898 cm NMR 0.84 and 1.01 (6H, 2s); 3.88 (1H, m); 4.72 and 5.0 (2H, 2m) 8 ppm MS:M =212(1);m/e: 194(1); (3); 151 (7); 140 (30); 125 (45); 95 (40); 84 (10); 69 (26); 55 (33); 43 (100); 29 (10).

2,6,6-Trimethy1-1-hydroxy-1-[ l-hydroxy-butyllcyclohex-Z-ene: yield about 5 By oxidation of this compound by means of CrO /pyridine there is ob tained 2,6,6-trimethyl- 1 -hydroxy- 1 -butyry1- cyclohex-2-ene [see Ex. 14].

EXAMPLE 12 7 Preparation of 2,6,6-trimethyl-l-[l-hydroxy-but-Z- 17 enyl]-; 2,6,6-trimethyl-l-[1-hydr0xy-but-3-enyl]- and 2.6,6-trimethyl- 1 1 -hydroxy-butyl]-1 ,2-epoxycyclohexane A solution of 0.1 mole of 2,6,6-trimethy1-1-[1- hydroxybut-2-enyl1-cyclohex-1-ene and 12 g of anhydrous sodium acetate in 30 ml of CH C1 at 15 is added to 21 g of a 40 solution of peracetic acid and 0.5 g of sodium acetate. The whole is allowed to stand for 3 hours, then the mixture is successively washed with water, a diluted NaHCO solution and again with water until neutrality. The separated organic phase is then concentrated and the resulting residue distilled. On separation by means of vapour phase chromatography (CARBOWAX column) the diastereoisomers are obtained in a pure state: 2,6,6-Trimethyl-l-[ 1-hydr0xy-but-2-enyl]- l ,2-

epoxycyclohexanezyield 80 7c; 22,, 1.4814; d, 0.9933 IR 3616, 3552, 965 cm NMR: 1.02 (2H, 25); 1.34 (3H, s); 1.7 (3H, d, .1 5 cps); 2.7 (1H, m); 4.36 (1H, m); 5.55 (2H, m) 6 ppm MS M =210 (0.1 m/e: 168 (1); 149 (10); 140 (39); 125 (93); 109 (16); 95 (14); 84 (24); 69 (49); 55 (50); 43 (100); 29 (14).

erythro-2,6,6-Trimethyl- 1 l-hydroxy-but-3-enyl1-1 ,2-

cpoxycyclohexanezyield 81 72; 11 1.4781; (1 0.9772

1R 3510, 3080, 1640, 990,910 cm NMR:1.0 and 1.02 (6H, 1.43 (3H, s); 3.91 (1H,

t, J I 6 cps); 4.8 6.2 (3H) 6 ppm MS M 2l0(O.1);m/e: l92(0.1); 169(2); 149(5); 140 (3); 125 (22); 109 (28); 95 (12); 83 (23); 69 (40); 55 (37); 43 (100 27 (12).

By replacing in the above described process 2,6,6- trimethy1-1-[ l-hydroxy-but-2-eny1]-cyc1ohex-1-ene by 2,6,6-trimethy1' 1 1-hydroxy-butylj-cyclohex-1-ene there are obtained: three-2.6,6-Trimethyl-1-[ l-hydroxy-butyll-l,2epoxycyclohexane:yield 10 76; 12,, 1.4760; (1 0.9819 1R 3637, 3510 cm NMR: 1.04 and 1.18 (6H, 25); 0.98 (3H, t, J 6 cps);

1.33 (3H, s); 3.46 (1H, m); 3.9 (1H, m) 6 ppm MS:-Trimet1iyl-(O.1); m/e: 183 (1); 165 (3); 151 (5);

erythro-Z.6,6-Trimethy1-1-[ l-hydroxy-buty1]-1.2-

epoxy-cyclohexanecyield 86 7a; 32 1.4687; (1 0.9705

IR 3510 Cm 118 NMR: 1.0 (6H, 25); 0.96 (3H, t, J=6 cps); 1.4 (3H, s);

2.55 (1H, m); 3.72 (1H, m) 6 ppm MS:M =212(0.1);m/e: 183(1); 165(3); 151 (7); 140 (3), 128 (42); 109 (15); (12); 85 (20); 71 (35); 55 (40); 43 29 (15).

EXAMPLE 13 Preparation of 2,6,6-trimethyl-1-[1-acetoxy-but-3- eny1]-, 2.6,6-trimethyl-l-ll-acetoxy-but-2-enylland 2,6,6-trimethyl-1 1-acetoxy-buty1]- 1 ,2-epoxycyclohexane The 2,6,6-trimethy1-1-{1-acetoxy-but-3-enyl]- and 2,6,6-trimethyl-1-[ 1-acetoxy-butyl]-cyc1ohex-l-ene used as starting products for the following epoxidation reaction are prepared by treating the corresponding carbinols with acetyl chloride in the presence of dimethylaniline according to the usual methods (see for example: R. B. Wagner and H. D. Zook, Synthetic Organic Chemistry, John Wiley, Inc., New York, p. 481 1956)).

2,6,6-Trimethyl-1-[1-acetoxy-but-3-eny1]-cyclohexl-ene: B.p. 63/0.1 Torr; a 1.4720; d, =0.9401 1R 1 1740 cm" 2,6,6-Trimethyl-1-l l-acetoxy-buty1]-cyclohex-1-ene:

B.p. 65/0.1 Torr; 11 1.4810; (1, 0.9521 1R 1738 cm 2,6,6-Trimethy1-1-[ 1-acetoxy-but-2-enyl]-cyclohexl-ene: B.p. 62/0.1 Torr; (1 0.9455; IR 1740 cm The preparation of the corresponding epoxides is carried out as indicated in Example 12. The analytical characteristics of the obtained compounds are given below: threo-2,6,6-Trimethy1-1-[1-acet0xy-but-3-enyl]-l,2-

epoxy-cyclohexanezyield 59 7:; mp. 3738 1R 1745 cm NMR:1.08(6H, 25); 1.38 (3H, s); 1.92 (3H, s); 5.1

(1H, m); 4.8-6.2 (3H) 6 ppm.

erythr0-2,6,6-Trimethyl-1-[ 1 -acetoxy-but-3-enyl]-l ,2-

epoxycyclohexanezyield 41 11 1.4685; df 1.009

1R 3080, 1740 cm, 1638, 990 and 910 cm NMR 0.98 and 1.02 (611,25); 1.38 (3H,s); 1.93 (3H,

s); 4.8-6.2 (3H); 4.96 (1H, m) 6 ppm threo-2,6,6-TRimethyl-1-[1-acetoxy-butyl]-1,2-epoxycyclohexane: yield 66 %;)1,, 1.4653; d =0.9959

IR 1745 cm NMR 0.97 and 1.03 (6H, 2s);0.96 (3H, t,.1= 6 cps);

1.37 (3H, s); 1.97 (3H, s); 5.37 (1H, m) 6 ppm erytro2,6,6-Trimethyl-1-1l-acetoxy-butyl]l,2-epoxycyclohexane: yield 34 11 1.4631; (1 1.000

1R 1745 cm NMR: 1.08 (6H, 25); 1.36 (3H, s); 1.94 (3H, s); 5.0

(1H, m) 6 ppm three-2,6,6-Trimethyl- 1 1 l-acet0xy-but-2-enyl1-l,2

epoxy-cyclohexanezyield 52 7;

IR 1742 cm" 19 erythro-2,6,6-Trimethyl-1-[ l -acetoxy-but-2-enyl]- l ,2

epoxy-cyclohexanezyield 47 /c; 1R 1738 cm MS M 252 EXAMPLE 14 Preparation of 2-methylene-6,6-dimethyl-l-hydroxy-1- [but-2-enoyl]-cyclohexane and 2,6,6-trimethyl-lhydroxy-l -[but-2-enoyl]-cyclohex-2-ene; 2- Methylene-6,6-dimethyl-l-hydroxyl-[but-3-enoyllcyclohexane and 2,6,6-trimethyl-l-hydroxy l-[but-3- enoyl]-cyclohex-2-ene; 2-Methylene-6,6-dimethyl-lhydroxy-l-butyryl-cyclohexane and 2,6,6-trimethyl-1- hydroxy-l-butyry1-cyclohex-2-ene 7.2 g of the products directly obtained by a sensitized photooxygenation of 2,6,6-trimethyl-1-[ l-hydroxy-but- 2-enyl]-cyclohex-1-ene followed by a reduction by means of Na so according to the process described in Example 9 are mixed within 24 hours, while vogorously stirring, with 40 g of freshly activated MnO in 200 ml of petroleum ether, in a nitrogen atmosphere. After separation by filtration of the excess MnO and distillation of the clear filtrate there are obtained 6.] g of a mixture comprising the desired products. The separation is effected by means of vapour phase chromatography. Z-Methylene'6,6-dimethyl-l-hydroxy-1-[but-2-enoyl]- cyclohexane:M.p. 707 1 IR 3500, 1810, 1690 and 885 cm NMR 10.88 and 0.98 (6H, 2s); 1.86 (3H, d, J 5 cps); 3.22 (1H, m); 4.94 and 5.13 (2H, 2m); 6.79 (1H, m) 6 ppm MS M =208 (6);m/e: 193 (3); 175 (0.1 165 (0.1); 152 (0.1); 139 (22); 123 (0.3); 111 (0.5); 95 (40); 81 (1); 69 (25); 55 (9); 43 (100); 27 (2).

2,6,6-Trimethyl-1-hydroxy-1-[but-2-enoyl]-cyclohex- 2-ene: 11,, 1.5049; (1 1.018

IR 3090, 1675, 1620, 970 cm" NMR 0.72 and 0.94 (61-1, 2s); 1.45 (3H, m); 1.92 (3H, d, J= 7.5 cps); 4.07 (1H, m); 5.7 (ll-l, m); 6.35-7.2 (m) 8 ppm MS M 208 (0.1); m/e: 190 (0.1); 175 (0.1); 152 (0.1); 139 (49); 121 (3); 109 (2); 95 (33); 69 (28); 55 (7); 43 (100); 27 (5).

2,6,6-Trimethyl-1-hydroxy-1-[but-3-enoyl]-cyclohex- 2-ene: B.p. 50/0.01 Torr; 11 1.4960; df" 0.9392

1R 3470, 1740 cm NMR 0.87 and 1.08 (6H, 1.98 (3H, d, J 7 cps);

4.7-6.1 (3H, m) 5 ppm 2-Methylene-6,6-dimethyl-1-hydroxy-1-[but-3-enoyl]- cyclohexane: 1R 3500, 1740, 1640, 990 cm NMR 0.88 and 1.05 (6H, 23); 4.7-6.l (31-1, m); 4.86

and 5.02 (2H, 2m) 5 ppm 2,6,6-Trimethyl-l -hydroxy-1-butyryl-cyclohex-2-ene:

1R 3450 and 1735 cm NMR 0.85 and 1.07 (6H, 25); 0.98 (3H, t, J 6 cps);

1.98 (3H, d, J 7 cps) 6 ppm Z-Methylene-6,6-dimethyl- 1 -hydroxyl-butyrylcyclohexane: IR 3500 and 1735 cm 20 NMR 10.88 and 1.07 (6H, 2s); 0.98 (3H, t, J=6 cps);

4.86 and 5.05 (2H, 2m) 8 ppm.

EXAMPLE 15 Preparation of 2,6,6-trimethyll -[but-2-enoyl cyclohexa-l ,3-diene 6 g of the mixture of keto-alcohols obtained according to the method described in Example 14 are mixed with 1.5 g of acidic diatomaceous earth in 30 ml of dioxane. The whole is heated for 3 hours at 105. Distillation of the reaction mixture gives the desired ketone in a yield of The analytical data are identical with those of a pure sample prepared according to Helv.

Chim. Acta, 53, 541 (1970).

EXAMPLE l6 lsomerization of 2-methylene-6,6-dimethyl-l-hydroxyl-[but-2-enoyll-cyclohexane into 2,6,6-trimethyl-lhydroxy-1-[but-2-enoyll-cyclohex-Z-ene 5 g of 2-methylene-6,6-dimethyl-1-hydroxy-l-[but-2- enoyll-cyclohexane, prepared according to the process described in Example 14, are refluxed in a nitrogen atmosphere in 30 ml of toluene with 0.5 g of iodine. After 4 hours the reaction mixture is cooled and treated with a concentrated aqueous Na SO solution until complete reduction of the excess iodine. After separation, the organic phase is washed with water, dried over MgSO and concentrated. Distillation of the thus obtained residue gives 4 g of a mixture comprising 30 of 2,6,6-trimethyl-1-hydroxy-l-[but-Z-enoyllcyclohex-Z-ene.

EXAMPLE l7 2-Methylene-6,6-dimethyl- 1 -hydroxyl l-hydroxybut-2-enyl]-cyclohexane a. 21 g of 40 peracetic acid in [-1 0 and 0.6 g of sodium acetate were added to a suspension of 19.4 g of 2,6,6-trimethyll 1-hydroxy-but-2-enyl]-cyclohexl-ene and 12 g of sodium acetate in 35 m1 of CH CI at 20 under nitrogen atmosphere. The whole was left for 2 hours at room temperature and whereupon 250 ml of H 0 were added therein.

The organic phase gave by distillation 19.5 g (93 yield) of 2,6,6-trimethyl-l-[ l-hydroxy-but-2-enyl]-1,2- epoxy-cyclohexane; b.p. 84/0.4 Torr; m, 1.4814; d 0.9933.

b. To 50 ml ofa 1N solution of lithium metal in ethylenediamine there were added under stirring in nitrogen atmosphere 10.5 g of the epoxide prepared according to the procedure described above. The reaction mixture was maintained vat ca. during 30 minutes, whereupon the excess of ethylenediamine was evaporated under reduced pressure. After neutralization by means of diluted acetic acid and subsequent fractional distillation there were obtained 2.35 g (22 yield) of an isomer mixture of 2-methylene-6,6-dimethyl-1- hydroxyl l-hydr0xy-but-2-enyl]-cyclohexane, the analytical data of which were in all respects identical with those of a sample prepared in accordance with the procedure described in Example 9.

When 2,6,6-trimethyll l-hydroxy-but-Z-enyllcyclohex-l-ene was replaced by 2,6,6-trimethyl-l-[lhydroxy-but-3-enyl]-cyclohex-l-ene or 2,6,6- trimethyll lhydroxy-butyl l-cyclohexl -ene there were obtained, by applying the same procedure as given above, the corresponding diol derivatives.

I claim:

1. A process for the preparation of unsaturated cycloaliphatic ketones of formula wherein R and R are the same or different and each represents a hydrogen atom or a lower alkyl radical comprising from one to six carbon atoms, which comprises treating a keto-alcohol of formula CO-CH=CH-CH3 UNITED STATES PATENT AND TRADEMARK OFFICE CE'HFICATE OF CORECTIUN PATENT NO. 3,892,809

DATED July 1, 1975 lN\/ ENTOR(S) Z KARL-HEINRICH SCHULTE-ELTE It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 4, line 64 "comprises" should read -comprised- Column 13, line 15 "prepared" should read prepare-.

Column 14, line 34 "1630" should read --l620.

Column 15, line 6 "&" should read 6.

Column 15 line 41 "0.02 Torr" should read 0.0l Torr.

Column 16, line 36 "ng" should read n Column 17, line 61 "-Trimethyl" should read 2l2-.

Column 17, line 66 "32" should read Column 18, line 51 "'IRimethyl" should read -'Irimethyl.

Column 18, line 58 "erytro" should read -erythro.

Signed and gealed this [SEAL] A ttest:

RUTH C. MASON Arresting Officer C. MARSHALL DANN Commissioner uj'larcr'rts and Trademarks thirteenth Day of April1976 

1. A PROCESS FOR THE PREPARATION OF UNSATURATED CYCLOALIPHATIC KETONES OF FORMULA
 2. A process according to claim 1, wherein the reaction is carried out in dioxan and at a temperature between about 90* and 100* C. 